Drop-hammer



W. A. KNAPP.

DROP HAMMER.

APPLICATION FILED NOV. 23. ms.

1,327,331, Patented Jan. 6,1920.

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WILLIAM A. KNAPP, 0F WAsrriNeroiv, nrs'rnror or COLUMBIA.

DROP-HAMMER.

Specification of Letters Patent.

Application filed. November 23, 1918. Serial N 0. 263,917.

To all whom it may concern:

Be it known that I, I/I ILLIAM A. KNA'PP, a citizen of the UnitedStates, and resident of Washington, District of Columbia, have inventedcertain new and useful Improvements in Drop-Hammers, of which thefollowing is a specification.

My invention is designed to provide a drop hammer, the stroke of whichwill be under the complete control of the operator, enabling him at willto get a lengthof stroke or drop of the hammer exactly suited to hisneeds.

The invention consists in the features and combination and arrangementof parts hereinafter described and particularly pointed out in theclaims.

In the accompanying drawings:

Figure l is a side elevation of a drop hammer embodying the invention.

Fig. 2 is a view looking from the left of Fig. l with the belts insection.

Fig. 3 is a detail of the sheath and drum associated therewith.

Fig. 4 is a sectional view of the sheath.

In these drawings 1 indicates a drop hammer, 2 a band or strap attachedthereto for lifting it, 3 a drum over which the band passes and 4: thehandle by which the-operator controls the operation of the hammer.

The drum 3 is fixed to the shaft 5 which is journaled in bearings 6 ofthe frame and carries a pulley 7 driven by a belt 8 by which arrangementthe drum 3 is rotated constantly in one direction.

Associated with this drum 3 is a sheath or controller 9. This may assumedifferent forms but in the particular form shown it consists of arms 10loosely mounted on the shaft 5 at the sides of the drum 3 and carryinga: cross piece 11 provided with a channel or space 12 receiving the band2. This sheath when in normal position, shown in Fig. l, rests with itsstop pin 13 bearing upon the frame and in this position the band 2 isout of frictional contact with the rotating drum 3 as indicated at a; orbears so lightly thereon as to have no lifting effect upon the hammer.When, however, the handle a is pulled down the controller 9 will beswung leftward, by the pull of the band 2, from the normal positionshown, with the result that the band will press upon the surface of therotary drum and the band will then lift the hammer and continue doing sountil the operator ceases to pull down or relieves the handle 4,whereupon the hammer will drop and the sheath will be swung.

to the right-into the normal p'ositiOn' shown 111 Fig. 1, being arrestedin this position by the stop pin 13 coming against the frame PatentedJam 6, 19-20.,

and in this position thebarrd2 will be held substantially free from thesurface ofthe revolving drum, which will nolonger have a lifting effectthereon. I p v It is obvious that the point "to which the hammer islifted and consequently the length of its drop maybe determined a-t thewill of the operator who needs only-to relieve 'the handle a of downwardpressure to cause the hammer to drop and thus the or light as he maydesire.

In order to positively establish slack the band 2 so that a materialportion of said band will be brought in contact with the surface of thedrum 3 before the lifting begins I provide a spring 14 "which willcreate slack at 15 so that when the handle at is pulled down the sheathwill swing through a considerable angle before the band straighten's outand therefore a considerable portion of the band will be in frictionalout departing from the principle in 'lved The stop pin holds the in myinvention. controller beyond the vertical center of its pivot.

It will be understood that where herein I refer to operating the hammerby hand I do so in a generic sense to include other manual control suchas by the foot.

In order toreturn the controller to its normal position with its stoppin 13 against the frame, I employ a spring 1.3 connected thereto and toa suitable fixed point.

I claim:

1. In combination a drop hammer, a revolving drum, a band passing overthe drum connected to the hammer and having a portion to be pulled uponby the operator, and a member mounted to have movement in a directioncircumferentially of the drum and engaging the band to normally free itfrom operative relation with the drum, said member when moved fromnormal position allowing the band to 'be operated by its frictionalcontact with the drum to raise the hammer, substantially as described.

operator can make the hammer blows heavy the top of the drum holding theband out of driving relation with the drum but moving circumferentiallyof the drum when the operator pulls upon the handle portion of the bandto cause the band to frictionally engage with and be driven by the drum,substantially as described.

3.- In combination a drop hammer, a revolving drum, a band attached tothe drop hammer and'passing over the drum, a controller member pivotallymounted and engaging the band to release or allow its frictional contactwith the drum, according to whether said member is in normal position oris moved therefrom, said band having a handle ortion to be pulled uponby the operator or swinging said member from normal position andbringing the band in contact'with the drum to be driven thereby.

4. In combination a drop hammer, a revolving drum, a band attached tothe hammer and passing over the drum, a controller member pivotallymounted and controlling the effective engagement of the band with thedrum and a stop for limiting the movement of the controller, said bandhaving a handle portion to be pulled by the operator for swinging thecontroller from its normal position and thereby permit the band tocontact with and be driven by the drum, substantially as described.

5. In combination, a hammer, a revolving drum, a band passing from thehammer over the drum, a controller engaging the band, and pivotallymounted on the shaft of the drum, said band having a handle portion bywhich the band may be pulled to swing the controller and thereby allowthe band to contact with and be lifted by the drum, substantially asdescribed.

6. In combination, a hammer, a revolving drum, a band passing from thehammer over the drum, acontroller engaging the band, and pivotallymounted on the shaft of the drum, said band having a handle portion bywhich the band may be pulled to swing the controller and thereby allowthe band to contact with and be lifted by the drum said controllercomprising arms and a cross piece, substantially as described.

7. In combination, a hammer, a band, a drum over which the band passes,a controller for regulating the contact of the band;

with the drum, said bandv having a handle portion which, when pulled,sets the controller in position to cause contact of the band with thedrum, and means for creating slack in the band, between the controllerand the hammer, substantially as described.

8. In combination, a hammer, a band, a drum over which the band passes,a controller for regulating the contact of the band with the drum, saidband having a handle portion which, when pulled, sets the controller inposition to cause contact of the V band with the drum, and means forcreating slack in the band, between the controller and the hammer, saidmeans consisting of a spring connected to the band and the hammer,substantially as described.

In testimony whereof, I aflix my signature.

WILLIAM A. KNAPP.

